公开(公告)号：US20030015262A1

公开(公告)日：2003-01-23

申请号：US10246449

申请日：2002-09-19

Applicant: NSK Ltd.

Inventor： Hiromichi Takemura ,  Yasuo Murakami ,  Youichi Matumoto ,  Seiji Sato

IPC: C21D009/40

CPC classification number: C21D9/40 ,  C22C38/18 ,  C22C38/22 ,  C23C8/18 ,  F16C19/06 ,  F16C33/30 ,  F16C33/62 ,  F16C33/6603 ,  F16C2202/04 ,  F16C2206/42 ,  F16C2240/60 ,  Y10T29/49705 ,  Y10T29/49707

Abstract: In a rolling bearing put under a working circumstance in which water tends to intrude into lubricants, it has been known such a phenomenon that hydrogen ions formed by decomposition of the lubricants are adsorbed to raceway surfaces and accumulated as hydrogen atoms in highly strained sites (in the vicinity of the position for maximum shearing stress), to cause stress corrosion cracking type peeling. The present invention provides a rolling bearing in which an oxide layer of an iron/chromium oxide series is formed at a thickness of from 1 to 1000 nm to at least one of raceway surfaces of bearing rings or rolling contact surfaces of rolling elements and a manufacturing method thereof. The oxide layer can inhibit hydrogen formed by decomposition of water incorporated in the lubricants from intruding into the matrix of the bearing members, thereby preventing early peeling for the raceway surfaces of the bearing rings or the rolling contact surfaces of the rolling elements and, thus, greatly improving the rolling life. The oxide layer can be formed simply by merely tempering the bearing member and then applying a re-heating treatment in air at a temperature lower than the tempering temperature.

Abstract translation: 在滚动轴承处于水倾向于侵入润滑剂的工作环境中的情况下，已经知道这样的现象，即通过润滑剂分解形成的氢离子被吸附在滚道表面上并且作为氢原子聚集在高应变位置（在 最大剪切应力位置附近），引起应力腐蚀开裂型剥离。 本发明提供一种滚动轴承，其中将铁/铬氧化物系列的氧化物层形成为1至1000nm的厚度至滚动元件的轴承圈或滚动接触表面的滚道表面中的至少一个，以及制造 方法。 氧化物层可以抑制由润滑剂中所含的水分解而形成的氢气侵入到轴承部件的基体中，从而防止滚动体的轴承圈或滚动面的滚道表面的早期剥离， 大大提高滚动寿命。 氧化物层可以简单地通过仅回火轴承构件，然后在低于回火温度的温度下在空气中进行再加热处理而形成。